Tuning Frequency for a sub (1 Viewer)

[Dean-P]

Hi

I am designing a new sub using Adire Audio's AV8 and playing with WinISD to do so.

The question I have is how do I know what tuning frequency I want?

By changing the tuning frequency, I find that I could almost use any size box but of course the tuning is different along with the port size/length.

I want a small size vented sub to match the Jordan JX92s in a 6L sealed box.

I planned on making the M8a but my wife wants a "small" speaker and the Jordans got rave reviews...so I guess I will dive into "full range" speakers.

Thanks Dean

 

[GrahamT]

I think I remember that a rule of thumb is to tune near the driver's Fs. That would be around 36 Hz. Also remember to check the the Q of the alignment you are designing. You probably want it somewhere near .7

 

[Rob Formica]

Ummmm… actually the idea of tuning a VENTED sub is to extend it's lower frequency response.

There are several schools of thought on that, but basically the *ideal* theoretical tuning is slightly below the driver/enclosure's natural roll-off (not actually the drivers Fs) so the response curve will give you a perfectly flat plateau. If you increase the enclosure size you can lower the tuning creating a double plateau with slightly reduced output but an extended bass response (often referred to EBS). Doing the opposite (decrease enclosure, raise tuning) has the opposite effect and creates a small bump in the response (often referred to as a punchy sub)

The Qb is an inherent characteristic of a sealed sub... and 0.7 to 0.5 is considered a flatter audiophile sub while >0.7 is a little more peaky.

Hope this helps...
Rob

 

[Dean-P]

thanks, I guess I will just use the defaults of winISD...